to check and start a process

[raj esh]

i am new to unix. please give the script
my script need to check a process running or not and if process is not running, script has to start that process.
assuming process as simple java program.

[Peter Johnson]

You can use the ps command to see what is running. To check for Java apps, use:

ps -ef | grep java

Alternately, you could use the jps app that comes with the JDK - it lists the Java processes running and gives the main class name.

AS far as a full script goes, you are on your own,: NotACodeMill

[Craig Jackson]

I would be careful when you "grep" for just for java. It may return other processes that use java.

Also when you execute the command 'grep java'. The actual command 'grep java' will show up in the process status queue.

One suggestion is to grep for the script that will execute the java program. This will only work if the script blocks while the java program program is running.

For example:
java_program_script.ksh:

 
#Main
AlreadyRunning=$(ps -ef | grep -c java_program_script)
if [[ ${AlreayRunning} -ne 2]]; then
     echo "script already running"
else
      echo  "run java program"
fi   

This is just one example.

[raj esh]

thanks a lot.
i understand the script . i will try to do this in bash shell.

[Tim Holloway]

PRX=`ps ax | grep catalina | grep -v grep | cut -f1 '-d '`
if [ $PRX -ne '' ];then
  echo "Tomcat is running on process #$PRX"
else
  echo "Tomcat is not running"
fi

[anish patil]

use pgrep see man pages for it
while using the ps use -w option ==> ps -aefww | grep tomat